Are they? I haven't seen a single report about that, I'd love it if you could provide a source.They're still begging to the Russians for the AL-41's
Again, they might not be as good as Western engines but it is still their engine. WS-15 reportedly has about the half service life as F119, yes still far behind, but they are improving. To say that they learn nothing from what they might see or wouldn't be able to replicate it anyway is simply wrong and arrogant.the engine tech they already have has 1/10th the endurance of the US equivalents. (example, 1000 hour engine life vs 10,000 hour life of the equivalent Western engine tech)
They took one decrepit, half finished aircraft carrier from Ukraine, built it, then built another one with improvements and now they are building their own. They did same with most of their jets, and through espionage or not, they managed to built a 5th generation jet. We would be foolish to put anything crucial and critical close to their sphere of influence.